“The more I travel,” Anthony Bourdain said, “the less I know.” It’s one of the tenets of the greatest travel series in television history. But Parts Unknown was more than a clarion call demanding you get out there and learn what you don’t know. It was also funny, poignant, ambitious filmmaking. The Takeout watched and reviewed all 95 episodes of Bourdain’s CNN series, then selected what we believe to be its 20 essential episodes. We hope it does for you what it did for us: Fill you with the urge to pack a bag and take off.